Actuator



Aug. 24, 1965 R. w. BURDEN ACTUATOR Urignal Filed April 23, 1962 ROBERTW. BURDEN IN VEN TOR.

BY gsfc, @TQM AGEN.'

United States Patent O 3,2tl2,tlo2 ACTUATR Robert W. Burden, Dallas,rlex., assigner to Ling-Torneo- Vought, lne., Dalias, Tex., acorporation of Delaware Original application Apr. 23, 1962, Ser. No.139,643, now Patent No. 3,152,522, dated ct. i3, i964. Divided and thisapplication Aug. 26, 11953, Ser. No. 304,557

6 Claims. (Cl. 92-SS) The present application is a division of theco-pending application Serial Number 189,643 filed April 23, 1962, l

since issued as U.S. Patent No. 3,152,522.

This invention relates to huid-powered actuators and means for mountingthe same and effecting connection into a fluid powering system and inparticular to an actuator in which the pivotal mounting means servesalso to connect the actuator into the fluid powering system.

While reference will be made herein, in describing the constructionsshown in the various figures of the drawing, to a hydraulic actuatoradapted for powering by a hydraulic system, it will be understood thatthe actuators shown are operable by other fluids, eg. a gas, suppliedunder pressure, and that the invention is not limited to an actuatorpowered by a hydraulic system.

A major object of the present invention is to provide an improvedactuator having pivotable means for attaching the actuator to a fixedstructure and carrying the'liow channels for connection of the actuatorinto a fluid powering system.

A related object is to provide an actuator and connecting and mountingmeans therefor which allow pivoting of the actuator `and dispense withilexible tubing for connecting the actuator into the fluid poweringsystem.

Other objects and advantages will be apparent from the specification andclaims and from the accompanying drawing illustrative of the invention.

In the drawing,

FIGURE 1 is a longitudinal, sectional view of an embodiment of theinvention;

FIGURE 2 is a longitudinal, sectional view of a form of the piston rodand tube employable in the embodiment shown in the previous ligure; and

FIGURE 3 is an end view of the tube end guide.

Referring now to FIGURE 1, an embodiment of the invention is shownwherein the piston 13A is movable relative to the `bulkhead 27A or otherfixed structure. The piston 13A divides the cylinder 10A into first andsecond chambers 14A, 15A and has therethrough a central, `axial opening.According to the nomenclature adopted, the cylinder first end wall 11Ais the one approached by the` piston 13A as the rod 16A is fullyretracted into the cylinder A. `The second end wall 12A,

`at the opposite end of the cylinder 10A, has a generally cylindricalopening through which the rod 16A extends, the latter beingconcentrically mounted on one face ol the piston 13A and having an end40A lying outside the cylinder and adapted for mechanical connection ofabody i to be moved by the actuator.

The ball A, rigidly mounted on one end of the cylin, der 19A, has ashank 19A which is threaded into an open. ing in, and thus rigidlyaiiixed to, the first end wall 11A, the ball `being on the outer end ofthe shank. The ball 20A is provided with mutually spaced, first andsecond ports 22A, 42, one in its crown and one, for example, at itsequator. As shown, more than one equatorial port 42 may be employed. Thespherical socket 24A receiving the ball 20A is adapted for mounting on abulkhead 27A or other fixed structure as by bolts 26A.

First and second ports 43, ld opening interiorly `of the socket `24A areadapted `for connection with respective hydraulic lines (not shown)through threaded openings bti Patented Aug. 24, i965 iiA, 3121A in theouter surface of the socket. The socket ports d3, i12- are made largerthan the ball ports 22A, fi?. with which they are `in register in orderthat they will continue to communicate with the .same throughout therange of pivoting of .the cylinder' lilA on the fixed structure ZA.

A rigid tube 118A has an open end sealingly and rigidly mounted in theball Ztl/A in communication with the first port 22A. The tube 18Aextends through a passage 21A in the ball ZliA and shank 19A into thecylinder second chamber 15A, thence through the central opening of thepiston iEiA into the piston rod 16A, which is provided with an axialpassage lA of larger diameter than the tube @A and extending from thepiston iEiA toward the rod outer end idr-i. The inner end of the rod ldAencircles and seals oit the axial opening in the piston 13A, and anyappropriate means are employed toseal between the tube 13A and piston13A where the tube slidably passes through the piston opening. Theportion of the tube 18A received within the rod passage 17A has a` freeend d5 which is open to provide communication between the respectiveinteriors of the tube ltA and rod 16A. At its outer end, the rod passage17A has a reduced-diameter portion d6 which is only slightly larger indiameter than the tube 13A and is entered by the tube free end 45 uponthe rod approaching complete retraction. The rod passage 17A isconnected with the cylinder first chamber MA through an opening i7 inthe rod 16A adjacent the piston 13A. The opening 47 is positioned to liewithin the cylindrical opening of the second end wall 12A, upon the rod16A approaching and reaching full extension, and thus to be at leas-tpartial-ly blocked by material of the second end Wall.

The passage 21A within the shank 19A and ball 20A 'is coaxial with therod passage 117A and terminates within the ball after intersection withthe ball second port 4t2. Thus fortminU a conduit coaxial with the tube15A, this passage 21A extends axially through the ball ZilA and shank19A and through an opening 51 in the inner end of the shank into thecylinder second chamber 15A, the

, opening being encircled by an annular flange or shoulder 36A with astraight-walled, cylindrical inner surface; Flow through theball-and-shank passage Zl-.A thus is external of the tube 18A.

On the face of the piston 13A adjacent the first end wall llA is ananular llange 37A whose straight-walled exterior surface is of onlyslightly less diameter than and mates closely with the correspondingsurf-ace of the end wall flange 36A, with which it is concentric, uponthe piston rod 16A approaching full retraction in the cylinder ltiA. lna typical application, the clearance between the mating surfaces of thetwo flanges 36A, 37A is .010 inch.

When, for example, hydraulic fluid `under pressure .is admitted into thefirstthreaded opening SGA, the orw is through the tube llA into the rodpassage 17A and from there into the cylinder first chamber 14A throughthe rod opening 47. The accompanying movement of the piston litA to theright, if continued to the end portion of the piston stroke, mates thetwo close-fitting flanges StEA, 37A encircling the opening 51 into theshank passage 21A and thus partially blocks outflow of fluid from thesecond chamber 15A into `the hydarulic return line (not shown) throughpassage ZtlA, ball second port (i2, and socket opening 34A andconsequently slows the rate` of retraction of the rod leA; whichretractionis stopped by the piston 13A striking the end wall flange 36A.At the same time, the tube free end. i5 enters the close-fitting,reduced-diameter portion do of the rod passage 17A, thus greatlyrestricting the flow of fluid under pressure into` the first chamberIAA. via the open line (not shown).

snoepen j retraction condition, and in this condition the free end 45 ofthe rod is supported in the rod passage reduceddiameter portion i6 andthus protected from the possibly deleterious effects of vibrations andlarge accelerations. It will be noted that `both the constructionwherein the i rod end 45 enters the pasasge reduced-diameter portionv yt5 and the construction wherein there is mating of matching tlanges 36A,37A cooperate to serve a common end, and that one or the other may beomitted as may be desired without loss of the needed snubbing of rodtravel upon complet-e retraction of the rod 16A.

Upon reversing the hydraulic ilow, iluid enters the `second threadedopening 34A, passes through the second ports 44, 42 of the socket andball, and flows through the shankV passage 21A into the second chamberESA, thus moving the piston 13A to the left. Displaced iluid flows fromthe cylinder first chamber 14A through the rod opening 47 into the rodpassage 17A, thence into the tube open end 45, through the tube 18A, andout the rst threaded opening 30A into a hydraulic system return As therod 16A nears full extension, its motion is snubbed by partial blockageof the rod opening 47 by material of the end wall EZA. It will beunderstood that a snubbing or slowing action is experienced, at eitherend of the stroke of the piston llSA,

`when the piston starts to move away from an adjacent one of the endwalls 11A or 12A as well as when, as described, it approaches one or theother of the end walls.

In FIGURE 2 the rod 16B is shown as having a passage 17B which does nothave at its outer end a reduceddiameter portion such las describedabove. All of the rod passage 17B through which the tube ISB extends iscylindrical and of the same diameter; and the tube ISB bears, rigidlymounted on its free end, a sliding guide 41S which engages the Wall ofthe passage 17B on each side of the tube 13B. In this way, the tube treeend is provided with support. The guide d8 may be of any suitablematerial such as metal or a heat-resistant, tough plastic, and its formmust be such as to leave a free ow-path between the open end of the tubeISB and the rod passage 17B adjacent the piston 13B, the guide forexample having four arms as shown in FIGURE 3. The -rod 16B, rod passage17B, and tube 18B otherwise may be made exactly as in FIGURE 1 and mayoptionally be employed in the actuator of FIGURE l.

Almost invariably, the body directly actuated by and to which ahydraulic motor is connected is a lever. Connection is at, -tor example,the rod end 40A (FIGURE l) of the actuator of the example. As the rod16A extends and retracts, therefore, the rod end 40A follows an arcuatepath, and the cylinder A is pivotally deflected relative to the fixedstructure 27A on which it is mounted. Thus, whereas the actuatorcenterline will be at a given location when the piston rod is at anintermediate point of extension, the actuator centerline often isdeflected in one direction at full retraction :and in an oppositedirection at full extension. The hydraulic system tubing (not shown) tothe actuator is in the form of metallic tubes rigidly mounted on fixedstructure relative to which the actuator is pivotable. To make hydraulicconnection into the two ends of the actuator, therefore, the connectingmeans employed must make allowance for the pivoting motion of theactuator. In the past, this has been accomplished by employing iiexibletubing in the terminal :portions of the two hydraulic lines to adoubleacting actuator. As the severity `of operating conditions lhasincreased, these lines have been rendered inadequate, for no knownmaterials of construction have been availiable which could enable themto withstand the operating pressures and temperatures involved and yetretain a lexible form. In a high-pressure line, for example, workingpressure commonly may stand at 4,00() psi., while pressure surges mayrange up to 6,000 psi.; meanwhile, the ambient air temperature may rangeto 650 F. To provide a tube flexible enough to withstand actuatorpivoting and yet capable of resisting the high temperatures andpressures involved, coiled metallic tubes have been employed to makehydraulic connection at each end of the actuator. While these have metwith a degree of success, their high bulk is very objectionable inaircraft applications, where limitations of space often preclude theiruse or make impossible their proper placement with respect to 'actuatormovement. Y

ln the present construction, no lexible tubing is employed; the actuatorvis connected to the hydraulic lines through rigid connection of thelatter to the ports MA, 34A and by means of the same structure ispivotally mounted on the bulkhead 27A. Rotation of the ball 29A in thesocket 24A allows motion of the actuator relative to the bulkhead 27Aand xed hydraulic ports, 30A, 34A, 28, while at the same timemaintaining duid-tight hydraulic connections.

While only one embodiment of the invention, together with severalmodifications thereof, has been described herein and shown in theaccompanying drawing, it will be evident that various furthermodications are possible in the arrangement and construction of itscomponents without departing from the scope of the invention.

I claim:

ll. In combination, t

a huid-powered actuator having a cylinder and a piston slidably dividingthe cylinder interior into rst and second chambers, the piston having anopening therethrough;

a rod mounted on one face of thepiston;

a ball rigidly mounted on one end of the cylinder;

a spherical socket receiving the ball and adapted for mounting on a nxedstructure;

mutually spaced, iirst and second ports in the ball;

a rigid tube xed relative to the ball and having a portion extendingaxially of the cylinder and sealingly and slidably through the pistonopening, thetube havingrcommunication with the rst port and said tubeportion having a free end;

a passage of larger diameter than the ktube and extending axially withinthe rod, which passage receives the tube portion extending -through thepiston and has an openingrconnecting the passage with the cylinder lirstchamber at a location adjacent the piston, the passage havingcommunication with the tube interior;

a passage connected with the second part and extending through the ball,said passage having a wall;

`an opening from the last-named passage into the second chamber;

and first and second ports in the socket adapted for connection withrespective lines of a iluid powering system and respectivelycommunicating, throughout a range of rotation of the ball in the socket,with the iirst :and second ports of the ball, the ball having a shank bymeans of which itis rigidly mounted on said one end of the cylinder,

said passage connected with the second port and extending through theball having extension within and axially of the shank to said openinginto the second chamber,

the tube extending through the shank within said passage connected withthe second port and having an end" rigidly and sealingly mounted withinthe ball in communication with the rst port, said tube having a wallradially spaced inwardly of said passage from said passage wall,

flow through the passage connected with the second port, within theshank, being external of the tube.

2. In combination,

a Huid-powered actuator having a cylinder and a piston slidably dividingthe cylinder interior into iirst and second chambers, the piston havingan opening therethrough;

-a rod mounted on one face of the piston;

a ball rigidly mounted on one end of the cylinder;

a spherical socket receiving the ball and adapted for mounting on afixed structure;

mutually spaced, rst and second ports in the ball;

a rigid tube fixed relative to the ball and having a portion extendingaxially of the cylinder and sealingly and slidably through the pistonopening, the tube having communication with the first port :and saidtube portion having a free end;

a passage of larger diameter than the tube and extending axially Withinthe rod, which passage receives the tube portion extending through thepiston and has an opening connecting the passage with the cylinder firstchamber at a location adjacent the piston, the passage havingcommunication with the tube interior;

a passage connected with the second port and extending through the ball,said passage having a wall;

an opening from the last-named passage into the second chamber;

:and first and second ports in the socket adapted for connection withrespective lines of a fluid powering system and respectivelycommunicating, throughout 'a range of rotation of the ball in thesocket, with the first and second ports of the ball, the cylinder:having :an end Wall with a cylindrical opening through which the rodextends,

the rod passage opening lying within the end wall cylindrical openingand being at least partially blocked by material of the end wall whenthe rod is fully extended from the cylinder.

3. In combination,

:a fluid-powered actuator having a cylinder and a piston slidablydividing the cylinder interior into first and second chambers, thepiston having an opening therethrough;

a rod mounted on one face of the piston;

a ball rigidly mounted on one end of the cylinder;

a spherical socket receiving the ball and adapted for mounting on afixed structure;

mutually spaced, first and second ports in the ball;

.a rigid tube fixed relative to the ball and having a portion extendingaxially of the cylinder and sealingly and slidably through the pistonopening, the tube having communication with the first port and said tubeportion having a free end;

a passage of larger diameter than the tube and extending axially Withinthe rod, which passage receives the tube portion extending through thepiston and has an opening connecting the passage` with the cylinderfirst chamber at a location adjacent the piston, the passage havingcommunication with the tube interior;

a passage connected with the second port and extending through the ball,said passage having a Wall;

an opening from the last-named passage into the second chamber;

and first and second ports in the socket adapted for connection withrespective lines of a fiuid powering system and respectivelycommunicating, throughout a range of rotation of the ball in the socket,with the first and second ports of the ball, the rod passage having aportion reduced to a diameter only slightly exceeding that of the tubefree end and into which reduced-diameter portion the tube free endsenters and remains upon complete retraction of the rod into thecylinder, said reduced-diameter portion of the rod passage being spacedand distinct for said piston opening.

4. In combination:

a cylinder having ends closed by first and second end walls each havinga central opening;

.a piston having therethrough a central opening and slidably mounted inthe cylinder for dividing the interior ofthe latter into rst and secondchambers;

an annular shoulder on a face of the piston spaced radially outwardlyfrom `and concentric with the piston opening;

an .annular shoulder on the first end wall concentric with the pistonshoulder and closely mated with the latter upon the piston reaching oneend of its stroke;

a shank rigidly fixed in the first end wall opening and having on itsouter end a ball;

-a first port in the crown and a second port `at the equator of theball;

a tube slidably and sealingly extend-ing through the piston opening andhaving a free end and an end rigidly fixed relative to the ball, theinterior of the tube communicating with the first port;

a rod concentrically mounted on the piston and extend- -ing through theopening of the second end wall;

a passage of greater diameter than thetube and extending axially in therod, the passage ext-ending from the piston opening toward the outer endof the rod;

a reduced-diameter portion of the passage of only slightly greaterdiameter than the tube and located where it is entered by the tube freeend upon complete retraction of the rod;

an opening from the rod exterior into its interior adjacent the piston,the rod opening being at least partially covered by material of thesecond end wall upon complete extension ofthe rod;

a passage in .the ball which opens into the second port and extendsthrough the shank into the second chamber in a location encircled by theannular shoulder of the first cap;

a socket receiving the ball and provided with means for mounting thesocket on a given fixed structure;

and first and second ports in the socket adapted for connection withrespective lines of a fluid powering system and respectivelycommunicating, throughout a range of pivoting of the shank on the fixedstructure, with the firstand second ports of the ball.

5. In a fluid-powered actuator having a cylinder, a

piston dividing the cylinder interior into first and second chambers, aport communicating with the second chamber, and means for connecting theport to a line of a fluid powering system, the construction comprising:

an axial opening through the piston;

a hollow rod enclosing a passageway communicating with the pistonopening, which rod is rigidly mounted on the piston for extensionthrough and from the first chamber and which has an opening adjacent thepiston and communicating between the first chamber and rod passage;

a tube of smaller diameter than the rod passage and having an endrigidly mounted relative to the cylinder;

means for connecting the tube end to a line of a fluid powering system;

a reduced-diameter portion of the rod passage spaced from the piston;

a portion of the tube slidingly and sealingly extending through thepiston opening and having a free end of only slightly less diameter thanthe rod passage reduced-diameter portion and received inl said portionwhen the rod is fully retracted into the cylinder; and structure rigidlyfixed relative to the cylinder and at least partially blocking theopening adjacent the piston upon and just prior to arrival of the rod atits position of full extension from the first chamber. 6. In a hydraulicactuator having a cylinder, a piston dividing the cylinder interior intofirst and second chambers, a port communicating with the second chamber,and means for connecting the port to a line of a fluid powering system,the construction comprising:

an axial opening through the piston;

a hollow rod enclosing a passageway communicating with the pistonopening, which rod is rigidly mounted =on the piston for extensionthrough and from the first chamber and which has an opening adjacent thepiston and communicating between the rst chamber and rod passage; Y

a -tube of smaller diameter than the rod passage and having an endrigidly mounted relative to the cylinder;4

means for connecting the tube end to a line of a iluid powering system;

an end wall of the cylinder approached by the piston as the rod isretracted to its fullest extent into the rst chamber;

an annular ange on said end wall with a straightwalled cylindricalsurface and enclosing said port communicating with the second chamber;

an annular ange on the piston with a straight-Walled cylindrical surfacewhich closely mates with the end wall annular flange cylindrical surfaceupon retraction of the rod to its fullest extent into the rst chamber;

(D ce and structure rigidly fixed relative to the cylinder and at leastpartially blocking the opening adjacent the piston upon and just priorto arrival of the rod -at its position of full extension from the irstchamber.

References Cited by the Examiner UNITED STATES PATENTS 908,414 12/08Mellin 92-1l9 1,098,157 5/14 Koken 92-113 1,500,921 7/24 Brarnson et al.92-119 1,717,485 6/29 Wirz 92-119 1,874,248 8/32 Davis 92-119 1,972,0178/34 Hulshizer 924113 2,293,167 8/42 Overbeke 92-119 3,023,739 3/62Dickson et al. 92-85 3,055,343 9/62 Kurt 92-110 FOREIGN VPATENTS 3,62412/ 64 Great Britain.

SAMUEL LEVINE, Primary Examiner.

RICHARD B. WILKINSON, Examiner.-

` Attesting Officer UNITED STATES PATENT OFFICE CERTIFICATE 0FCORRECTION Patent No 3, 202 ,062 August 24, 196

Robert W. Burden error appears in the above numbered pat- It is herebycertified that t the said Letters Patent should read as ent requiringcorrection and tha corrected below.

Column '2, line 63, for "hydarulic" read hydraulic Column 4, line 50,for "part" read port column 5, line 7l, for "fr" 'read from Signed andsealed this 15th day of March 1966.

(SEAL) Attest:

ERNEST W. SWIDER 'EDWARD I. BRENNER Commissioner of Patents

1. IN COMBINATION, A FLUID-POWERED ACTUATOR HAVING A CYLINDER AND APISTON SLIDABLY DIVIDING THE CYLINDER INTERIOR INTO FIRST AND SECONDCHAMBERS, THE PISTON HAVING AN OPENING THERETHROUGH; A ROD MOUNTED ONONE FACE OF THE PISTON; A BALL RIGIDLY MOUNTED ON ONE END OF THECYLINDER; A SPHERICAL SOCKET RECEIVING THE BALL AND ADAPTED FOR MOUNTINGON A FIXED STRUCTURE; MUTUALLY SPACED, FIRST AND SECOND PORTS IN THEBALL; A RIGID TUBE FIXED RELATIVE TO THE BALL AND HAVING A PORTIONEXTENDING AXIALLY OF THE CYLINDER AND SEALINGLY AND SLIDABLY THROUGH THEPISTON OPENING, THE TUBE HAVING COMMUNICATION WITH THE FIRST PORT ANDSAID TUBE PORTION HAVING A FREE END; A PASSAGE OF LARGER DIAMETER THANTHE TUBE AND EXTENDING AXIALLY WITHIN THE ROD, WHICH PASSAGE RECEIVESTHE TUBE PORTION EXTENDING THROUGH THE PISTON AND HAS AN OPENINGCONNECTING THE PASSAGE WITH THE CYLINDER FIRST CHAMBER AT A LOCATIONADJACENT THE PISTON, THE PASSAGE HAVING COMMUNICATION WITH THE TUBEINTERIOR; A PASSAGE CONNECTED WITH THE SECOND PART AND EXTENDING THROUGHTHE BALL, SAID PASSAGE HAVING A WALL; AN OPENING FROM THE LAST-NAMEDPASSAGE INTO THE SECOND CHAMBER; AND FIRST AND SECOND PORTS IN THESOCKET ADAPTED FOR CONNECTION WITH RESPECTIVE LINES OF A FLUID POWERINGSYSTEM AND RESPECTIVELY COMMUNICATING, THROUGHOUT A RANGE OF ROTATION OFTHE BALL IN THE SOCKET, WITH THE FIRST AND SECOND PORTS OF THE BALL, THEBALL HAVING A SHANK BY MEANS OF WHICH IT IS RIGIDLY MOUNTED ON SAID ONEEND OF THE CYLINDER, SAID PASSAGE CONNECTED WITH THE SECOND PORT ANDEXTENDING THROUGH THE BALL HAVING EXTENSION WITHIN AND AXIALLY OF THESHANK TO SAID OPENING INTO THE SECOND CHAMBER, THE TUBE EXTENDINGTHROUGH THE SHANK WITHIN SAID PASSAGE CONNECTED WITH THE SECOND PORT ANDHAVING AN END RIGIDLY AND SEALINGLY MOUNTED WITHIN THE BALL INCOMMUNICATION WITH THE FIRST PORT, SAID TUBE HAVING A WALL RADIALLYSPACED INWARDLY OF SAID PASSAGE FROM SAID PASSAGE WALL, FLOW THROUGH THEPASSAGE CONNECTED WITH THE SECOND PORT, WITHIN THE SHANK, BEING EXTERNALOF THE TUBE.